My finished henin.
The base is constructed using 2 layers of cotton canvas that has been stiffened with fusable facing. I sewed boning around the bottom and top edges. I sewed a length of boning up the center front, with a small portion extended to make the loop. I sewed a piece of boning up the back. I covered the base with black wool and hand tacked it in place. I sewed the cone together at the back. The veil is help on the front with 2 large pins and I used 2 small pins to hold it down at the top back.
Overall I think it turned out quite well and it fits me perfectly! I shouldn't need to use anything to secure it to my head, it simply sits there perfectly balanced, which is what it is supposed to do.